As shown in FIG. 1, a scooter rear brake of the prior art has a rear wheel cover which is mounted on the footboard such that the rear wheel cover is located over the rear wheel for bringing about a braking effect on the rear wheel by pressing the rear wheel cover against the rear wheel. The rear wheel cover is apt to swing aside to press against the rear wheel incorrectly, thereby undermining the braking effect. In addition, the contact area between the rear wheel cover and the rear wheel is not large enough to have a sufficient friction.